Browsing by Author "Garcia, G."
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- Bioaccessible (poly)phenol metabolites from raspberry protect neural cells from oxidative stress and attenuate microglia activationPublication . Garcia, G.; Nanni, S.; Figueira, I.; Ivanov, I.; McDougall, G. J.; Stewart, D.; Ferreira, R. B.; Pinto, Paula; Silva, R. F. M.; Brites, D.; Nunes Dos Santos, CláudiaNeuroinflammation is an integral part of the neurodegeneration process inherent to several aging dysfunctions. Within the central nervous system, microglia are the effective immune cells, responsible for neuroinflammatory responses. In this study, raspberries were subjected to in vitro digestion simulation to obtain the components that result from the gastrointestinal (GI) conditions, which would be bioaccessible and available for blood uptake. Both the original raspberry extract and the gastrointestinal bioaccessible (GIB) fraction protected neuronal and microglia cells against H2O2-induced oxidative stress and lipopolysaccharide (LPS)-induced inflammation, at low concentrations. Furthermore, this neuroprotective capacity was independent of intracellular ROS scavenging mechanisms. We show for the first time that raspberry metabolites present in the GIB fraction significantly inhibited microglial pro-inflammatory activation by LPS, through the inhibition of Iba1 expression, TNF-alpha release and NO production. Altogether, this study reveals that raspberry polyphenols may present a dietary route to the retardation or amelioration of neurodegenerative-related dysfunctions. (C) 2016 Elsevier Ltd. All rights reserved.
- Polyphenols journey through blood-brain barrier towards neuronal protectionPublication . Figueira, I.; Garcia, G.; Pimpão, R.; Terrasso, C.; Costa, I.; Almeida, A.; Tavares, L.; Pais, T.; Pinto, Paula; Ventura, M.; Filipe, A.; McDougall, G.; Stewart, D:; Kim, S.; Palmela, I.; Brites, D.; Brito, M.; Santos, C.Age-related complications such as neurodegenerative disorders are increasing and remain cureless. The possibility of altering the progression or the development of these multifactorial diseases through diet is an emerging and attractive approach with increasing experimental support. We examined the potential of known bioavailable phenolic sulfates, arising from colonic metabolism of berries, to infuence hallmarks of neurodegenerative processes. In silico predictions and in vitro transport studies across blood-brain barrier (BBB) endothelial cells, at circulating concentrations, provided evidence for diferential transport, likely related to chemical structure. Moreover, endothelial metabolism of these phenolic sulfates produced a plethora of novel chemical entities with further potential bioactivies. Pre-conditioning with phenolic sulfates improved cellular responses to oxidative, excitotoxicity and infammatory injuries and this attenuation of neuroinfammation was achieved via modulation of NF-κB pathway. Our results support the hypothesis that these small molecules, derived from dietary (poly)phenols may cross the BBB, reach brain cells, modulate microglia-mediated infammation and exert neuroprotective efects, with potential for alleviation of neurodegenerative diseases.